軟件開發的目標是減少耦合,讓模塊以前關係清晰.javascript
MVC模式在軟件開發中常常和ORM模式一塊兒應用,主要做用是將(數據抽象,數據實體傳輸和前臺數據展現)分層,這樣前臺,後臺,數據庫三層分離,減少耦合.html
1)Model : 負責抽象並存儲數據庫數據前端
2)Controller : 負責數據的轉化和傳輸java
3)View : 負責展現數據mysql
注意 框架的應用使軟件開發變得更有章可循,更規範化,軟件開發的每一個職責都落到了具體的模塊中去jquery
ORM框架 : 將數據庫數據封裝存儲至Model類中web
MVC框架 : 前臺數據與實體數據的互爲轉化ajax
開發者 : 配置框架,編寫業務代碼,前臺數據展現頁面spring
SpringMVC是創建在Spring framework之上的一個MVC框架,主要的組件有前端控制器、處理器映射器、處理器適配器、視圖解析器.sql
1.SpringMVC的原理就如上圖所展現的,客戶端發來HTTP請求,
2.前端控制器做爲一個頂層執行者獲取請求,
3.返回一個執行鏈HandlerExecutionChain{HandlerInterceptor1,HandlerInterceptor2,Handler},
4.前端控制器請求映射器查詢對應的處理器適配器,
5.處理器適配器代理執行處理器,
6.處理器響應處理,返回一個ModelAndView,
7.適配器返回一個ModelAndView至前端控制器
8.前端控制器請求視圖解析器執行解析,
9.解析器返回一個未經渲染的視圖
10.前端控制器渲染視圖,將模型數據存於request域
11.視圖發至瀏覽器進行渲染呈現
注意,上圖分爲Model,View,Controller等模塊,其中Model裏面可封裝許多邏輯,這一部分未在步驟上進行說明.
1.SpringMVC的前端入口是一個名爲DispatchServlet的servlet,Struts2是一個Filter過濾器;
2.SpringMVC基於方法進行開發(一個url對應一個方法),請求參數傳遞到方法的形參,能夠設計爲單例或者多例模式,Struts2是基於類開發,傳遞的參數經過類的屬性進行傳遞;
3.Struts2採用值棧存儲請求和響應,經過OGNL存取數據,SpringMVC經過參數解析器將request內容進行解析,並給方法形參賦值,將數據和視圖封裝成一個ModelAndView對象,最後將ModelAndView的數據傳入request中以及視圖渲染,JSP使用JSTL來進行取值操做;
1.前端控制器DispatcherServlet(無需開發者開發)
做用 : 接收請求,響應結果,至關於轉發器,中央處理器.
有了DispatcherServlet減小了其它組件之間的耦合度.
類位置 org.springframework.web.servlet.DispatcherServlet.class
配置文件 /org/springframework/web/servlet/DispatcherServlet.properties
<servlet> <servlet-name>springmvc</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:springmvc.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>springmvc</servlet-name> <url-pattern>*.action</url-pattern> </servlet-mapping>
2.處理器映射器HandlerMapping(無需開發者開發)
做用:根據請求的url查找Handler和Interceptor攔截器,
將它們封裝在HandlerExecutionChain 對象中給前端控制器返回.
類位置 org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping.class
<!—beanName Url映射器 --> <bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping"/>
org.springframework.web.servlet.handler.SimpleUrlHandlerMapping.class
<!— 簡單url映射 simpleUrlHandlerMapping是BeanNameUrlHandlerMapping的加強版本,它能夠將url和處理器bean的id進行統一映射配置 --> <bean class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping"> <property name="mappings"> <props> <prop key="/items1.action">controller的bean id</prop> <prop key="/items2.action">controller的bean id</prop> </props> </property> </bean>
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping.class
<bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping"/>
3.處理器適配器HandlerAdapter(無需開發者開發)
做用:按照特定規則(HandlerAdapter要求的規則)去執行Handler
類位置 org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.class
<!-- 全部實現了org.springframework.web.servlet.mvc.Controller 接口的Bean經過此適配器進行適配、執行. --> <bean class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter" />
org.springframework.web.servlet.mvc.HttpRequestHandlerAdapter.class
<!-- 全部實現了org.springframework.web.HttpRequestHandler 接口的Bean經過此適配器進行適配、執行. --> <bean class="org.springframework.web.servlet.mvc.HttpRequestHandlerAdapter"/>
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.class
<!-- 註解時使用的Adapter,配合註解映射器一塊兒使用 --> <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter"/>
4.處理器Handler(需開發者開發)
注意:編寫Handler時按照HandlerAdapter的要求去作,這樣適配器才能夠去正確執行Handler
非註解方式
package com.harry.controller; import java.util.ArrayList; import java.util.List; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.springframework.web.servlet.ModelAndView; import org.springframework.web.servlet.mvc.Controller; import com.harry.entity.Items; /*** * @author harry * 用於處理頁面請求, * 數據來源是經過數據庫ORM映射至實體類來獲取, * 這裏使用靜態獲取數據進行簡單演示. */ public class ItemList_1 implements Controller { @Override public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws Exception { //調用service查找 數據庫,查詢商品列表,這裏使用靜態數據模擬 List<Items> itemsList = new ArrayList<Items>(); //向list中填充靜態數據 Items items_1 = new Items(); items_1.setName("聯想筆記本"); items_1.setPrice(6000f); items_1.setDetail("ThinkPad T430 聯想筆記本電腦!"); Items items_2 = new Items(); items_2.setName("蘋果手機"); items_2.setPrice(5000f); items_2.setDetail("iphone6蘋果手機!"); itemsList.add(items_1); itemsList.add(items_2); //返回ModelAndView ModelAndView modelAndView = new ModelAndView(); //至關 於request的setAttribut,在jsp頁面中經過itemsList取數據 modelAndView.addObject("itemsList", itemsList); //指定視圖 modelAndView.setViewName("Items/itemList"); return modelAndView; } }
註解方式
@Controller public class ItemList_2 { /* RequestMappingHandlerMapping將對類中標記@ResquestMapping的方法進行映射,根據ResquestMapping定義的url匹配ResquestMapping標記的方法,匹配成功返回HandlerMethod對象給前端控制器,HandlerMethod對象中封裝url對應的方法Method */ @RequestMapping("/queryItem.action") public ModelAndView queryItem() { // 商品列表 List<Items> itemsList = new ArrayList<Items>(); Items items_1 = new Items(); items_1.setName("聯想筆記本"); items_1.setPrice(6000f); items_1.setDetail("ThinkPad T430 聯想筆記本電腦!"); Items items_2 = new Items(); items_2.setName("蘋果手機"); items_2.setPrice(5000f); items_2.setDetail("iphone6蘋果手機!"); itemsList.add(items_1); itemsList.add(items_2); // 建立modelAndView準備填充數據、設置視圖 ModelAndView modelAndView = new ModelAndView(); // 填充數據 modelAndView.addObject("itemsList", itemsList); // 視圖 modelAndView.setViewName("order/itemsList"); return modelAndView; } }
注意,註解方式應使用註解包掃描<context:component-scan base-package="com.harry.controller"/>,
包掃描能夠掃描到@Bean,@Controller,@Service,@Repository等註解類.
RequestMappingHandlerMapping,HttpRequestHandlerAdapter(<mvc:annotation-driven>可自動加載這兩個類)
5.視圖解析器View resolver(無需開發者開發)
做用:進行視圖解析,根據邏輯視圖名解析成真正的視圖(view)
類位置 org.springframework.web.servlet.view.InternalResourceViewResolver.class
<!-- ViewResolver配置 --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/> <property name="prefix" value="/WEB-INF/jsp/"/> <property name="suffix" value=".jsp"/> </bean>
6.視圖View(需開發者開發)
View是一個接口,實現類支持不一樣的View類型(jsp、freemarker、pdf...)
springmvc的開發,須要配置上述工做流中的組件,入門程序緊接着框架應用:Mybatis - 開發詳述的案例進行開發,
1.備份數據庫,實體類
-- MySQL dump 10.13 Distrib 5.7.18, for Linux (x86_64) -- -- Host: localhost Database: mybatis -- ------------------------------------------------------ -- Server version 5.7.18-0ubuntu0.16.04.1 /*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */; /*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */; /*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */; /*!40101 SET NAMES utf8 */; /*!40103 SET @OLD_TIME_ZONE=@@TIME_ZONE */; /*!40103 SET TIME_ZONE='+00:00' */; /*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */; /*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */; /*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */; /*!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */; -- -- Table structure for table `items` -- DROP TABLE IF EXISTS `items`; /*!40101 SET @saved_cs_client = @@character_set_client */; /*!40101 SET character_set_client = utf8 */; CREATE TABLE `items` ( `id` int(11) NOT NULL AUTO_INCREMENT, `name` varchar(32) NOT NULL COMMENT '商品名稱', `price` float(10,1) NOT NULL COMMENT '商品訂價', `detail` text COMMENT '商品描述', `pic` varchar(64) DEFAULT NULL COMMENT '商品圖片', `createtime` datetime NOT NULL COMMENT '生產日期', PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8; /*!40101 SET character_set_client = @saved_cs_client */; -- -- Dumping data for table `items` -- LOCK TABLES `items` WRITE; /*!40000 ALTER TABLE `items` DISABLE KEYS */; INSERT INTO `items` VALUES (1,'臺式機',3000.0,'該電腦質量很是好!!!!',NULL,'2015-02-03 13:22:53'),(2,'筆記本',6000.0,'筆記本性能好,質量好!!!!!',NULL,'2015-02-09 13:22:57'),(3,'揹包',200.0,'名牌揹包,容量大質量好!!!!',NULL,'2015-02-06 13:23:02'); /*!40000 ALTER TABLE `items` ENABLE KEYS */; UNLOCK TABLES; -- -- Table structure for table `orderdetail` -- DROP TABLE IF EXISTS `orderdetail`; /*!40101 SET @saved_cs_client = @@character_set_client */; /*!40101 SET character_set_client = utf8 */; CREATE TABLE `orderdetail` ( `id` int(11) NOT NULL AUTO_INCREMENT, `orders_id` int(11) NOT NULL COMMENT '訂單id', `items_id` int(11) NOT NULL COMMENT '商品id', `items_num` int(11) DEFAULT NULL COMMENT '商品購買數量', PRIMARY KEY (`id`), KEY `FK_orderdetail_1` (`orders_id`), KEY `FK_orderdetail_2` (`items_id`), CONSTRAINT `FK_orderdetail_1` FOREIGN KEY (`orders_id`) REFERENCES `orders` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION, CONSTRAINT `FK_orderdetail_2` FOREIGN KEY (`items_id`) REFERENCES `items` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION ) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8; /*!40101 SET character_set_client = @saved_cs_client */; -- -- Dumping data for table `orderdetail` -- LOCK TABLES `orderdetail` WRITE; /*!40000 ALTER TABLE `orderdetail` DISABLE KEYS */; INSERT INTO `orderdetail` VALUES (1,3,1,1),(2,3,2,3),(3,4,3,4),(4,4,2,3); /*!40000 ALTER TABLE `orderdetail` ENABLE KEYS */; UNLOCK TABLES; -- -- Table structure for table `orders` -- DROP TABLE IF EXISTS `orders`; /*!40101 SET @saved_cs_client = @@character_set_client */; /*!40101 SET character_set_client = utf8 */; CREATE TABLE `orders` ( `id` int(11) NOT NULL AUTO_INCREMENT, `user_id` int(11) NOT NULL COMMENT '下單用戶id', `number` varchar(32) NOT NULL COMMENT '訂單號', `createtime` datetime NOT NULL COMMENT '建立訂單時間', `note` varchar(100) DEFAULT NULL COMMENT '備註', PRIMARY KEY (`id`), KEY `FK_orders_1` (`user_id`), CONSTRAINT `FK_orders_id` FOREIGN KEY (`user_id`) REFERENCES `user` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION ) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8; /*!40101 SET character_set_client = @saved_cs_client */; -- -- Dumping data for table `orders` -- LOCK TABLES `orders` WRITE; /*!40000 ALTER TABLE `orders` DISABLE KEYS */; INSERT INTO `orders` VALUES (3,1,'1000010','2015-02-04 13:22:35',NULL),(4,1,'1000011','2015-02-03 13:22:41',NULL),(5,10,'1000012','2015-02-12 16:13:23',NULL); /*!40000 ALTER TABLE `orders` ENABLE KEYS */; UNLOCK TABLES; -- -- Table structure for table `user` -- DROP TABLE IF EXISTS `user`; /*!40101 SET @saved_cs_client = @@character_set_client */; /*!40101 SET character_set_client = utf8 */; CREATE TABLE `user` ( `id` int(11) NOT NULL AUTO_INCREMENT, `username` varchar(32) NOT NULL COMMENT '用戶名稱', `birthday` date DEFAULT NULL COMMENT '生日', `sex` char(1) DEFAULT NULL COMMENT '性別', `address` varchar(256) DEFAULT NULL COMMENT '地址', PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=27 DEFAULT CHARSET=utf8; /*!40101 SET character_set_client = @saved_cs_client */; -- -- Dumping data for table `user` -- LOCK TABLES `user` WRITE; /*!40000 ALTER TABLE `user` DISABLE KEYS */; INSERT INTO `user` VALUES (1,'王五',NULL,'2',NULL),(10,'張三','2014-07-10','1','北京市'),(16,'張小明',NULL,'1','河南鄭州'),(22,'陳小明',NULL,'1','河南鄭州'),(24,'張三丰',NULL,'1','河南鄭州'),(25,'陳小明',NULL,'1','河南鄭州'),(26,'王五',NULL,NULL,NULL); /*!40000 ALTER TABLE `user` ENABLE KEYS */; UNLOCK TABLES; /*!40103 SET TIME_ZONE=@OLD_TIME_ZONE */; /*!40101 SET SQL_MODE=@OLD_SQL_MODE */; /*!40014 SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS */; /*!40014 SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS */; /*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */; /*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */; /*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */; /*!40111 SET SQL_NOTES=@OLD_SQL_NOTES */; -- Dump completed on 2017-10-10 0:00:04
package com.harry.entity; import java.util.Date; public class Items { private Integer id; private String name; private Float price; private String pic; private Date createtime; private String detail; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name == null ? null : name.trim(); } public Float getPrice() { return price; } public void setPrice(Float price) { this.price = price; } public String getPic() { return pic; } public void setPic(String pic) { this.pic = pic == null ? null : pic.trim(); } public Date getCreatetime() { return createtime; } public void setCreatetime(Date createtime) { this.createtime = createtime; } public String getDetail() { return detail; } public void setDetail(String detail) { this.detail = detail == null ? null : detail.trim(); } }
package com.harry.entity; import java.util.Date; import java.util.List; public class Orders { private Integer id; private Integer userId; private String number; private Date createtime; private String note; //用戶信息 private User user; //訂單明細 private List<Orderdetail> orderdetails; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public Integer getUserId() { return userId; } public void setUserId(Integer userId) { this.userId = userId; } public String getNumber() { return number; } public void setNumber(String number) { this.number = number == null ? null : number.trim(); } public Date getCreatetime() { return createtime; } public void setCreatetime(Date createtime) { this.createtime = createtime; } public String getNote() { return note; } public void setNote(String note) { this.note = note == null ? null : note.trim(); } public User getUser() { return user; } public void setUser(User user) { this.user = user; } public List<Orderdetail> getOrderdetails() { return orderdetails; } public void setOrderdetails(List<Orderdetail> orderdetails) { this.orderdetails = orderdetails; } @Override public String toString() { return "Orders [id=" + id + ", userId=" + userId + ", number=" + number + ", createtime=" + createtime + ", note=" + note + ", user=" + user + ", orderdetails=" + orderdetails + "]"; } }
package com.harry.entity; public class Orderdetail { private Integer id; private Integer ordersId; private Integer itemsId; private Integer itemsNum; //明細對應的商品信息 private Items items; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public Integer getOrdersId() { return ordersId; } public void setOrdersId(Integer ordersId) { this.ordersId = ordersId; } public Integer getItemsId() { return itemsId; } public void setItemsId(Integer itemsId) { this.itemsId = itemsId; } public Integer getItemsNum() { return itemsNum; } public void setItemsNum(Integer itemsNum) { this.itemsNum = itemsNum; } public Items getItems() { return items; } public void setItems(Items items) { this.items = items; } @Override public String toString() { return "Orderdetail [id=" + id + ", ordersId=" + ordersId + ", itemsId=" + itemsId + ", itemsNum=" + itemsNum + "]"; } }
package com.harry.entity; import java.io.Serializable; import java.util.Date; import java.util.List; @SuppressWarnings("serial") public class User implements Serializable { //屬性名和數據庫表的字段對應 private int id; private String username;// 用戶姓名 private String sex;// 性別 private Date birthday;// 生日 private String address;// 地址 //用戶建立的訂單列表 private List<Orders> ordersList; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getSex() { return sex; } public void setSex(String sex) { this.sex = sex; } public Date getBirthday() { return birthday; } public void setBirthday(Date birthday) { this.birthday = birthday; } public String getAddress() { return address; } public void setAddress(String address) { this.address = address; } @Override public String toString() { return "User [id=" + id + ", username=" + username + ", sex=" + sex + ", birthday=" + birthday + ", address=" + address + "]"; } public List<Orders> getOrdersList() { return ordersList; } public void setOrdersList(List<Orders> ordersList) { this.ordersList = ordersList; } }
2.導入spring ioc, aop, mvc, log4j...的jar包,這裏使用maven
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/cache http://www.springframework.org/schema/jdbc/spring-cache.xsd "> <modelVersion>4.0.0</modelVersion> <groupId>com.harry</groupId> <artifactId>harry-ssm</artifactId> <packaging>war</packaging> <version>0.0.1-SNAPSHOT</version> <name>harry-ssm Maven Webapp</name> <url>http://maven.apache.org</url> <dependencies> <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis --> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.4.1</version> </dependency> <!-- https://mvnrepository.com/artifact/log4j/log4j --> <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>1.2.17</version> </dependency> <!-- https://mvnrepository.com/artifact/org.springframework/spring-core --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>4.3.11.RELEASE</version> </dependency> <!-- https://mvnrepository.com/artifact/org.springframework/spring-aop --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aop</artifactId> <version>4.3.11.RELEASE</version> </dependency> <!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>4.3.11.RELEASE</version> </dependency> <!-- https://mvnrepository.com/artifact/junit/junit --> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> <scope>test</scope> </dependency> <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.40</version> </dependency> <!-- https://mvnrepository.com/artifact/taglibs/standard --> <dependency> <groupId>taglibs</groupId> <artifactId>standard</artifactId> <version>1.1.2</version> </dependency> <!-- https://mvnrepository.com/artifact/javax.servlet/jstl --> <dependency> <groupId>javax.servlet</groupId> <artifactId>jstl</artifactId> <version>1.2</version> </dependency> </dependencies> <build> <finalName>harry-ssm</finalName> </build> </project>
3.配置前端控制器,springmvc的入口組件
<!-- contextConfigLocation指定springmvc的主配置文件地址,如不指定則默認爲WEB-INF/[DispatcherServlet 的Servlet 名字]-servlet.xml <load-on-startup>1</load-on-startup> 服務器啓動時建立 <url-pattern>*.action</url-pattern> 攔截地址指明全部.action結尾的地址 --> <servlet> <servlet-name>springmvc</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:springmvc.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>springmvc</servlet-name> <url-pattern>*.action</url-pattern> </servlet-mapping>
4.配置處理器適配器
<!-- 配置處理器適配器:簡單處理器適配器 全部實現了org.springframework.web.servlet.mvc.Controller 接口的Bean做爲Springmvc的後端控制器。 --> <bean class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter"/>
5.配置處理器
package com.harry.controller; import java.util.ArrayList; import java.util.List; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.springframework.web.servlet.ModelAndView; import org.springframework.web.servlet.mvc.Controller; import com.harry.entity.Items; /*** * @author harry * 用於處理頁面請求, * 數據來源是經過數據庫ORM映射至實體類來獲取, * 這裏使用靜態獲取數據進行簡單演示. */ public class ItemList_1 implements Controller { @Override public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws Exception { //調用service查找 數據庫,查詢商品列表,這裏使用靜態數據模擬 List<Items> itemsList = new ArrayList<Items>(); //向list中填充靜態數據 Items items_1 = new Items(); items_1.setName("聯想筆記本"); items_1.setPrice(6000f); items_1.setDetail("ThinkPad T430 聯想筆記本電腦!"); Items items_2 = new Items(); items_2.setName("蘋果手機"); items_2.setPrice(5000f); items_2.setDetail("iphone6蘋果手機!"); itemsList.add(items_1); itemsList.add(items_2); //返回ModelAndView ModelAndView modelAndView = new ModelAndView(); //至關 於request的setAttribut,在jsp頁面中經過itemsList取數據 modelAndView.addObject("itemsList", itemsList); //指定視圖 modelAndView.setViewName("Items/itemList"); return modelAndView; } }
<!-- controller配置 --> <bean name="/items1.action" id="itemList1" class="cn.itcast.springmvc.controller.first.ItemList1"/>
6.配置處理器映射器
<!-- 處理器映射器 --> <!-- 根據bean的name進行查找Handler 將action的url配置在bean的name中 --> <bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping" />
7.配置視圖解析器
<!-- ViewResolver配置 JstlView 指視圖使用jstl類庫支持 prefix,前綴 suffix,後綴 --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/> <property name="prefix" value="/WEB-INF/jsp/"/> <property name="suffix" value=".jsp"/> </bean>
8.編寫視圖
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ page isELIgnored ="false" %> <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %> <%@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>查詢商品列表</title> </head> <body> 商品列表: <table width="100%" border=1> <tr> <td>商品名稱</td> <td>商品價格</td> <td>商品描述</td> </tr> <c:forEach items="${itemsList }" var="item"> <tr> <td>${item.name}</td> <td>${item.price}</td> <td>${item.detail}</td> </tr> </c:forEach> </table> </body> </html>
9.訪問http://localhost:8080/harry-ssm/items1.action
描述的工做流與上面畫的圖一致,只不過此次使用源碼來進行流程分析.
1.讀取context中的配置,初始化各大組件
2.客戶端發來請求,DispatchServlet接收請求,觸發doService方法,doService方法調用doDispatch方法
3.doDispatch調用getHandler獲取Handler,調用getHandlerAdapter獲取Adapter
4.getHandler經過HandlerMapping對象返回HandlerExecutionChain
5.從HandlerExecutionChain中獲取Handler並交由HandlerAdapter執行
6.獲取的ModelAndView對象,調用render方法渲染
7.render方法經過調用視圖解析器來獲取視圖
8.DispatchServlet渲染視圖,將Model數據放在request域中
9.客戶端讀取響應
Spring整合Mybatis這個ORM框架已經在 框架應用:Mybatis - 開發詳述 整合過了,如今三個框架進行整合.
須要完成的工做其實就是處理這關係線:
User <--> View <--> Action <--> Service <--> DAO <--> DB
---------------------Spring-------------------
DAO層鏈接數據庫須要要數據源信息db.properties,框架須要log4j.properties,mybatis的總配置文件sqlMapConfig.xml,使用spring來配置數據源,管理事務,配置SqlSessionFactory和mapper掃描器的applicationContext-dao.xml,Mapper對象的配置文件XXXMapper.xml.
Service層用spring配置service接口applicationContext-service.xml,配置事務管理applicationContext-transaction.xml,Service接口
Action層springmvc配置文件springmvc.xml,web.xml中配置DispatchServlet,配置編碼轉換器,加載spring容器,Controller類
DAO
jdbc.driver=com.mysql.jdbc.Driver jdbc.url=jdbc:mysql://localhost:3306/mybatis jdbc.username=XXXX jdbc.password=XXXX
# Global logging configuration,建議開發環境中要用debug log4j.rootLogger=DEBUG, stdout # Console output... log4j.appender.stdout=org.apache.log4j.ConsoleAppender log4j.appender.stdout.layout=org.apache.log4j.PatternLayout log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd"> <configuration> <!—使用自動掃描器時,mapper.xml文件若是和mapper.java接口在一個目錄則此處不用定義mappers --> <mappers> <package name="com.harry.ssm.mapper" /> </mappers> </configuration>
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd "> <!-- 加載配置文件 --> <context:property-placeholder location="classpath:db.properties"/> <!-- 數據庫鏈接池 --> <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close"> <property name="driverClassName" value="${jdbc.driver}"/> <property name="url" value="${jdbc.url}"/> <property name="username" value="${jdbc.username}"/> <property name="password" value="${jdbc.password}"/> <property name="maxActive" value="30"/> <property name="maxIdle" value="5"/> </bean> <!-- 讓spring管理sqlsessionfactory 使用mybatis和spring整合包中的 --> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <!-- 數據庫鏈接池 --> <property name="dataSource" ref="dataSource" /> <!-- 加載mybatis的全局配置文件 --> <property name="configLocation" value="classpath:mybatis/SqlMapConfig.xml" /> </bean> <!-- mapper掃描器 --> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="basePackage" value="com.harry.ssm.mapper"></property> <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/> </bean> </beans>
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> <mapper namespace="com.harry.ssm.mapper.ItemsMapper"> <!-- sql片斷 --> <!-- 商品查詢條件 --> <sql id="query_items_where"> <if test="items!=null"> <if test="items.name!=null and items.name!=''"> and items.name like '%${items.name}%' </if> </if> </sql> <!-- 查詢商品信息 --> <select id="findItemsList" parameterType="queryVo" resultType="items"> select * from items <where> <include refid="query_items_where"/> </where> </select> </mapper>
public interface ItemsMapper { //商品列表 public List<Items> findItemsList(QueryVo queryVo) throws Exception; }
Service
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd "> <!-- 商品管理的service --> <bean id="itemsService" class="com.harry.ssm.service.impl.ItemsServiceImpl"/> </beans>
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd "> <!-- 事務管理器 對mybatis操做數據庫事務控制,spring使用jdbc的事務控制類 --> <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <!-- 數據源 dataSource在applicationContext-dao.xml中配置了 --> <property name="dataSource" ref="dataSource"/> </bean> <!-- 通知 --> <tx:advice id="txAdvice" transaction-manager="transactionManager"> <tx:attributes> <!-- 傳播行爲 --> <tx:method name="save*" propagation="REQUIRED"/> <tx:method name="delete*" propagation="REQUIRED"/> <tx:method name="insert*" propagation="REQUIRED"/> <tx:method name="update*" propagation="REQUIRED"/> <tx:method name="find*" propagation="SUPPORTS" read-only="true"/> <tx:method name="get*" propagation="SUPPORTS" read-only="true"/> <tx:method name="select*" propagation="SUPPORTS" read-only="true"/> </tx:attributes> </tx:advice> <!-- aop --> <aop:config> <aop:advisor advice-ref="txAdvice" pointcut="execution(* com.harry.ssm.service.impl.*.*(..))"/> </aop:config> </beans>
package com.harry.ssm.service; import java.util.List; import com.harryt.ssm.po.ItemsCustom; import com.harry.ssm.po.ItemsQueryVo; public interface ItemsService { //商品查詢列表 public List<ItemsCustom> findItemsList(ItemsQueryVo itemsQueryVo) throws Exception; //根據id查詢商品信息 /** * * <p>Title: findItemsById</p> * <p>Description: </p> * @param id 查詢商品的id * @return * @throws Exception */ public ItemsCustom findItemsById(Integer id) throws Exception; //修改商品信息 /** * * <p>Title: updateItems</p> * <p>Description: </p> * @param id 修改商品的id * @param itemsCustom 修改的商品信息 * @throws Exception */ public void updateItems(Integer id,ItemsCustom itemsCustom) throws Exception; }
package com.harry.ssm.service.impl; import java.util.List; import org.springframework.beans.BeanUtils; import org.springframework.beans.factory.annotation.Autowired; import com.harry.ssm.mapper.ItemsMapper; import com.harry.ssm.mapper.ItemsMapperCustom; import com.harry.ssm.po.Items; import com.harry.ssm.po.ItemsCustom; import com.harry.ssm.po.ItemsQueryVo; import com.harry.ssm.service.ItemsService; public class ItemsServiceImpl implements ItemsService{ @Autowired private ItemsMapperCustom itemsMapperCustom; @Autowired private ItemsMapper itemsMapper; @Override public List<ItemsCustom> findItemsList(ItemsQueryVo itemsQueryVo) throws Exception { //經過ItemsMapperCustom查詢數據庫 return itemsMapperCustom.findItemsList(itemsQueryVo); } @Override public ItemsCustom findItemsById(Integer id) throws Exception { Items items = itemsMapper.selectByPrimaryKey(id); //中間對商品信息進行業務處理 //.... //返回ItemsCustom ItemsCustom itemsCustom = new ItemsCustom(); //將items的屬性值拷貝到itemsCustom BeanUtils.copyProperties(items, itemsCustom); return itemsCustom; } @Override public void updateItems(Integer id, ItemsCustom itemsCustom) throws Exception { //添加業務校驗,一般在service接口對關鍵參數進行校驗 //校驗 id是否爲空,若是爲空拋出異常 //更新商品信息使用updateByPrimaryKeyWithBLOBs根據id更新items表中全部字段,包括 大文本類型字段 //updateByPrimaryKeyWithBLOBs要求必須轉入id itemsCustom.setId(id); itemsMapper.updateByPrimaryKeyWithBLOBs(itemsCustom); } }
Action
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd "> <!-- 掃描controller註解,多個包中間使用半角逗號分隔 --> <context:component-scan base-package="com.harry.ssm.controller"/> <!--註解映射器 --> <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping"/> <!--註解適配器 --> <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter"/> <!-- ViewResolver --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="viewClass" value="org.springframework.web.servlet.view.JstlView" /> <property name="prefix" value="/WEB-INF/jsp/" /> <property name="suffix" value=".jsp" /> </bean> </beans>
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5"> <display-name>springmvc</display-name> <!-- 加載spring容器 --> <context-param> <param-name>contextConfigLocation</param-name> <param-value>/WEB-INF/classes/spring/applicationContext.xml,/WEB-INF/classes/spring/applicationContext-*.xml</param-value> </context-param> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <!-- 解決post亂碼 --> <filter> <filter-name>CharacterEncodingFilter</filter-name> <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> <init-param> <param-name>encoding</param-name> <param-value>utf-8</param-value> </init-param> </filter> <filter-mapping> <filter-name>CharacterEncodingFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <!-- springmvc的前端控制器 --> <servlet> <servlet-name>springmvc</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <!-- contextConfigLocation不是必須的, 若是不配置contextConfigLocation, springmvc的配置文件默認在:WEB-INF/servlet的name+"-servlet.xml" --> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:spring/springmvc.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>springmvc</servlet-name> <url-pattern>*.action</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>index.html</welcome-file> <welcome-file>index.htm</welcome-file> <welcome-file>index.jsp</welcome-file> <welcome-file>default.html</welcome-file> <welcome-file>default.htm</welcome-file> <welcome-file>default.jsp</welcome-file> </welcome-file-list> </web-app>
package com.harry.ssm.controller; import java.util.List; import javax.servlet.http.HttpServletRequest; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.servlet.ModelAndView; import com.harry.ssm.po.ItemsCustom; import com.harry.ssm.service.ItemsService; @Controller //爲了對url進行分類管理 ,能夠在這裏定義根路徑,最終訪問url是根路徑+子路徑 //好比:商品列表:/items/queryItems.action @RequestMapping("/items") public class ItemsController { @Autowired private ItemsService itemsService; // 商品查詢 @RequestMapping("/queryItems") public ModelAndView queryItems(HttpServletRequest request) throws Exception { //測試forward後request是否能夠共享 System.out.println(request.getParameter("id")); // 調用service查找 數據庫,查詢商品列表 List<ItemsCustom> itemsList = itemsService.findItemsList(null); // 返回ModelAndView ModelAndView modelAndView = new ModelAndView(); // 至關 於request的setAttribut,在jsp頁面中經過itemsList取數據 modelAndView.addObject("itemsList", itemsList); // 指定視圖 // 下邊的路徑,若是在視圖解析器中配置jsp路徑的前綴和jsp路徑的後綴,修改成 // modelAndView.setViewName("/WEB-INF/jsp/items/itemsList.jsp"); // 上邊的路徑配置能夠不在程序中指定jsp路徑的前綴和jsp路徑的後綴 modelAndView.setViewName("items/itemsList"); return modelAndView; } //商品信息修改頁面顯示 //@RequestMapping("/editItems") //限制http請求方法,能夠post和get // @RequestMapping(value="/editItems",method={RequestMethod.POST,RequestMethod.GET}) // public ModelAndView editItems()throws Exception { // // //調用service根據商品id查詢商品信息 // ItemsCustom itemsCustom = itemsService.findItemsById(1); // // // 返回ModelAndView // ModelAndView modelAndView = new ModelAndView(); // // //將商品信息放到model // modelAndView.addObject("itemsCustom", itemsCustom); // // //商品修改頁面 // modelAndView.setViewName("items/editItems"); // // return modelAndView; // } @RequestMapping(value="/editItems",method={RequestMethod.POST,RequestMethod.GET}) //@RequestParam裏邊指定request傳入參數名稱和形參進行綁定。 //經過required屬性指定參數是否必需要傳入 //經過defaultValue能夠設置默認值,若是id參數沒有傳入,將默認值和形參綁定。 public String editItems(Model model,@RequestParam(value="id",required=true) Integer items_id)throws Exception { //調用service根據商品id查詢商品信息 ItemsCustom itemsCustom = itemsService.findItemsById(items_id); //經過形參中的model將model數據傳到頁面 //至關於modelAndView.addObject方法 model.addAttribute("itemsCustom", itemsCustom); return "items/editItems"; } //商品信息修改提交 @RequestMapping("/editItemsSubmit") public String editItemsSubmit(HttpServletRequest request,Integer id,ItemsCustom itemsCustom)throws Exception { //調用service更新商品信息,頁面須要將商品信息傳到此方法 itemsService.updateItems(id, itemsCustom); //重定向到商品查詢列表 // return "redirect:queryItems.action"; //頁面轉發 //return "forward:queryItems.action"; return "success"; } }
View
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %> <%@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>查詢商品列表</title> </head> <body> <form action="${pageContext.request.contextPath }/item/queryItem.action" method="post"> 查詢條件: <table width="100%" border=1> <tr> <td><input type="submit" value="查詢"/></td> </tr> </table> 商品列表: <table width="100%" border=1> <tr> <td>商品名稱</td> <td>商品價格</td> <td>生產日期</td> <td>商品描述</td> <td>操做</td> </tr> <c:forEach items="${itemsList }" var="item"> <tr> <td>${item.name }</td> <td>${item.price }</td> <td><fmt:formatDate value="${item.createtime}" pattern="yyyy-MM-dd HH:mm:ss"/></td> <td>${item.detail }</td> <td><a href="${pageContext.request.contextPath }/items/editItems.action?id=${item.id}">修改</a></td> </tr> </c:forEach> </table> </form> </body> </html>
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %> <%@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>修改商品信息</title> </head> <body> <form id="itemForm" action="${pageContext.request.contextPath }/items/editItemsSubmit.action" method="post" > <input type="hidden" name="id" value="${itemsCustom.id }"/> 修改商品信息: <table width="100%" border=1> <tr> <td>商品名稱</td> <td><input type="text" name="name" value="${itemsCustom.name }"/></td> </tr> <tr> <td>商品價格</td> <td><input type="text" name="price" value="${itemsCustom.price }"/></td> </tr> <tr> <td>商品生產日期</td> <td><input type="text" name="createtime" value="<fmt:formatDate value="${itemsCustom.createtime}" pattern="yyyy-MM-dd HH:mm:ss"/>"/></td> </tr> <%-- <tr> <td>商品圖片</td> <td> <c:if test="${item.pic !=null}"> <img src="/pic/${item.pic}" width=100 height=100/> <br/> </c:if> <input type="file" name="pictureFile"/> </td> </tr> --%> <tr> <td>商品簡介</td> <td> <textarea rows="3" cols="30" name="detail">${itemsCustom.detail }</textarea> </td> </tr> <tr> <td colspan="2" align="center"><input type="submit" value="提交"/> </td> </tr> </table> </form> </body> </html>
定義於Controller類及其方法上,用於指定訪問的url的文件映射路徑和訪問方法,如
@RequestMapping("/items")
public class ItemsController {@RequestMapping("/queryItems",method={RequestMethod.POST,RequestMethod.GET})
public ModelAndView queryItems(HttpServletRequest request) throws Exception {那麼,指定的路徑爲http://localhost:8080/appName/items/queryitems.action,有POST和GET兩種訪問方式
ModelAndView 對象可添加model數據和指定view
void 能夠利用內部跳轉進行響應,或者重定向,或者響應json數據
request.getRequestDispatcher("頁面路徑").forward(request, response);
response.sendRedirect("url")
String 指定邏輯視圖名,重定向,內部跳轉
return "item/editItem";
return "redirect:queryItem.action";
return "forward:editItem.action";
參數綁定能夠是客戶端數據綁定,也能夠是服務端參數綁定;
服務端參數綁定就是在request<--controller這個過程之間發生的事,request到達controller控制權就在咱們的手上,咱們能夠運行本身的邏輯代碼,而後獲取參數,而後再將其綁定在request域中,等着給DispatchServlet渲染.
支持的類型:HttpServletRequest,HttpServletResponse,HttpSession,Model/ModelMap
Items item = itemService.findItemById(id);
model.addAttribute("item", item);
modelMap是model接口實現類,實質上都是實例化ModelMap來存儲key/value
頁面經過${item.xxx}來取值.
客戶端參數綁定就是request-->controller,將客戶填入的數據進行自動獲取至方法上
支持的類型:基礎類型(Bollean,Integer,String,Float/Double),POJO,自定義類型轉換器,集合類
public String editItem(Model model,Integer id,Boolean status) throws Exception
http://localhost:8080/springmvc_mybatis/item/editItem.action?id=2&status=false參數id和status將自動獲取
@RequestParam 經常使用來處理基礎類型
public String editItem(@RequestParam(value="item_id",required=true) String id
@RequestParam(value="item_status",defaultValue="true") Boolean status) {}
頁面定義
<input type="text" name="name"/>
<input type="text" name="price"/>
Controller方法定義,獲取items匹配的屬性名name,price
@RequestMapping("/editItemSubmit")
public String editItemSubmit(Items items)throws Exception{
System.out.println(items);
自定義類型轉換器
CustomDateConverter.javapublic class CustomDateConverter implements Converter<String, Date> { @Override public Date convert(String source) { try { SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); return simpleDateFormat.parse(source); } catch (Exception e) { e.printStackTrace(); } return null; } }
springmvc.xml<mvc:annotation-driven conversion-service="conversionService"> </mvc:annotation-driven> <!-- conversionService --> <bean id="conversionService" class="org.springframework.format.support.FormattingConversionServiceFactoryBean"> <!-- 轉換器 --> <property name="converters"> <list> <bean class="com.harry.controller.converter.CustomDateConverter"/> </list> </property> </bean>
集合類
StringArray<input type="checkbox" name="item_id" value="001"/> <input type="checkbox" name="item_id" value="002"/> <input type="checkbox" name="item_id" value="003"/> ------------------------------------------------------------------------- public String deleteitem(String[] item_id)throws Exception{ System.out.println(item_id); }
List<c:forEach items="${itemsList }" var="item" varStatus="s"> <tr> <td><input type="text" name="itemsList[${s.index }].name" value="${item.name }"/></td> <td><input type="text" name="itemsList[${s.index }].price" value="${item.price }"/></td> ..... ..... </tr> </c:forEach> ----------------------------------------------------------------------------------------------------- public class QueryVo { private List<Items> itemList;//商品列表 //get/set方法.. } ----------------------------------------------------------------------------------------------------- public String useraddsubmit(Model model,QueryVo queryVo)throws Exception{ System.out.println(queryVo.getItemList()); }
Map<tr> <td>學生信息:</td> <td> 姓名:<inputtype="text"name="itemInfo['name']"/> 年齡:<inputtype="text"name="itemInfo['price']"/> .. .. .. </td> </tr> ---------------------------------------------------------------------------------------- public class QueryVo { private Map<String, Object> itemInfo = new HashMap<String, Object>(); //get/set方法.. } ----------------------------------------------------------------------------------------- public String useraddsubmit(Model model,QueryVo queryVo)throws Exception{ System.out.println(queryVo.getStudentinfo()); }
咱們在工做中通常使用逆向工程生成工具來進行代碼開發,也就是ORM裏面的實體部分已是自動生成的,這部分的代碼不能動,由於很容易形成代碼混亂,可是咱們又常常須要去修改裏面的部分屬性;
咱們常常還碰到另一種狀況,就是客戶端請求的多是包含幾個類的視圖(如多值查詢),那麼針對這種狀況,咱們可使用一個包裝類來做爲視圖類,而後返回視圖類來進行響應,而咱們上面也是這麼作的.
鑑於上述緣由,咱們會使用自定義類來對其進行封裝,使用視圖類來進行傳輸,這樣,咱們就能夠在不碰那些代碼的前提下任意進行代碼修改.
相信你在開發時必定碰到過亂碼問題,SpringMVC也提供了一個統一的編碼過濾器,可是隻適用於POST編碼過濾,這是由於開發中上傳表單數據都規定使用POST,因此SpringMVC也就只提供這一種過濾器.
<filter> <filter-name>CharacterEncodingFilter</filter-name> <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> <init-param> <param-name>encoding</param-name> <param-value>utf-8</param-value> </init-param> </filter> <filter-mapping> <filter-name>CharacterEncodingFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping>
還有GET的亂碼解決方案有兩種,
1.修改tomcat配置文件添加編碼與工程編碼一致
<Connector URIEncoding="utf-8" connectionTimeout="20000" port="8080" protocol="HTTP/1.1" redirectPort="8443"/>
2.對參數進行從新編碼
String userName = new String(request.getParamter("userName").getBytes("ISO8859-1"),"utf-8");
數據校驗通常都會在前端進行,可是有時安全性要求高點的環境下,也會在服務端進行數據校驗.
服務端校驗
Controller層 檢驗頁面請求的合法性,在服務端控制層conroller校驗,不區分客戶端類型(瀏覽器、手機客戶端、遠程調用)
Service層 不區分客戶端類型(瀏覽器、手機客戶端、遠程調用)
DAO層 通常不進行校驗
SpringMVC使用校驗框架Validation.
校驗思路:
頁面提交請求的參數,請求到controller方法中,使用validation進行校驗.若是校驗出錯,將錯誤信息展現到頁面.
1.導入Bean-Validation框架jar包,Hibernate-validator
2.配置校驗器
<!-- 校驗器 --> <bean id="validator" class="org.springframework.validation.beanvalidation.LocalValidatorFactoryBean"> <!-- hibernate校驗器--> <property name="providerClass" value="org.hibernate.validator.HibernateValidator" /> <!-- 指定校驗使用的資源文件,在文件中配置校驗錯誤信息,若是不指定則默認使用classpath下的ValidationMessages.properties --> <property name="validationMessageSource" ref="messageSource" /> </bean> <!-- 校驗錯誤信息配置文件 --> <bean id="messageSource" class="org.springframework.context.support.ReloadableResourceBundleMessageSource"> <!-- 資源文件名--> <property name="basenames"> <list> <value>classpath:CustomValidationMessages</value> </list> </property> <!-- 資源文件編碼格式 --> <property name="fileEncodings" value="utf-8" /> <!-- 對資源文件內容緩存時間,單位秒 --> <property name="cacheSeconds" value="120" /> </bean> <!--註解映射器 --> <!-- <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping"/> --> <!--註解適配器 --> <!-- <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter"/> --> <!-- 使用 mvc:annotation-driven代替上邊註解映射器和註解適配器配置 mvc:annotation-driven默認加載不少的參數綁定方法, 好比json轉換解析器就默認加載了,若是使用mvc:annotation-driven不用配置上邊的RequestMappingHandlerMapping和RequestMappingHandlerAdapter 實際開發時使用mvc:annotation-driven --> <mvc:annotation-driven conversion-service="conversionService" validator="validator"></mvc:annotation-driven>
3.在POJO中添加校驗規則.
4.配置校驗時產生的message
5.捕獲校驗錯誤信息
在須要校驗的pojo前邊添加@Validated,在須要校驗的pojo後邊添加BindingResult bindingResult接收校驗出錯信息
注意:@Validated和BindingResult bindingResult是配對出現,而且形參順序是固定的(一前一後).
6.controller傳遞錯誤信息
7.頁面顯示錯誤信息
8.校驗分組
在pojo中定義校驗規則,而pojo是被多個 controller所共用,當不一樣的controller方法對同一個pojo進行校驗,可是每一個controller方法須要不一樣的校驗.能夠指定不一樣的分組來進行校驗.
9.在校驗中添加分組
10.在Controller指定分組的校驗規則
數據回顯指提交數據後出現錯誤,將剛纔提交的數據回顯到剛纔的提交頁面,好比填一張表,填完後一項錯誤後從新回到提交前的狀態.
1.SpringMVC默認對POJO進行回顯.
pojo數據傳入controller方法後,springmvc自動將pojo數據放到request域,key等於pojo類型(首字母小寫)
2.@ModelAttribute
@ModelAttribute能夠指定POJO對應的key值,頁面獲取能夠直接使用key值進行獲取,還能夠將返回值存入request域
3.直接使用model.addAttribute
異常處理思路很簡單,就是DAO,Service,Controller出現異常直接向上拋出,而後在DispatchServlet那一層設置一個異常處理器就處理全部異常.
1.建立自定義Exception
package com.harry.exception; @SuppressWarnings("serial") public class ExceptionCustom extends Exception { //異常信息 public String message; public ExceptionCustom(String message){ super(message); this.message = message; } public String getMessage() { return message; } public void setMessage(String message) { this.message = message; } }
2.定義全局異常處理器
全局異常處理器處理思路:
解析出異常類型;
若是該異常類型是系統自定義的異常直接取出異常信息,在錯誤頁面展現;
若是該異常類型不是系統自定義的異常,構造一個自定義的異常類(信息爲"未知錯誤");
實現SpringMVC提供的HandlerExceptionResolver接口
package com.harry.exception; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.springframework.web.servlet.HandlerExceptionResolver; import org.springframework.web.servlet.ModelAndView; public class ExceptionCustomResolver implements HandlerExceptionResolver { /** * (非 Javadoc) * <p>Title: resolveException</p> * <p>Description: </p> * @param request * @param response * @param handler * @param ex 系統 拋出的異常 * @return * @see org.springframework.web.servlet.HandlerExceptionResolver#resolveException(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse, java.lang.Object, java.lang.Exception) */ @Override public ModelAndView resolveException(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) { //handler就是處理器適配器要執行Handler對象(只有method) // 解析出異常類型 // 若是該 異常類型是系統 自定義的異常,直接取出異常信息,在錯誤頁面展現 // String message = null; // if(ex instanceof ExceptionCustom){ // message = ((ExceptionCustom)ex).getMessage(); // }else{ //// 若是該 異常類型不是系統 自定義的異常,構造一個自定義的異常類型(信息爲「未知錯誤」) // message="未知錯誤"; // } //上邊代碼變爲 ExceptionCustom ExceptionCustom = null; if(ex instanceof ExceptionCustom){ ExceptionCustom = (ExceptionCustom)ex; }else{ ExceptionCustom = new ExceptionCustom("未知錯誤"); } //錯誤信息 String message = ExceptionCustom.getMessage(); ModelAndView modelAndView = new ModelAndView(); //將錯誤信息傳到頁面 modelAndView.addObject("message", message); //指向錯誤頁面 modelAndView.setViewName("error"); return modelAndView; } }
錯誤頁面
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>錯誤提示</title> </head> <body> ${message } </body> </html>
springmvc.xml配置全局異常處理器
<!-- 全局異常處理器 只要實現HandlerExceptionResolver接口就是全局異常處理器 --> <bean class="cn.itcast.ssm.exception.CustomExceptionResolver"></bean>
1.當提交的表單數據混合幾種數據格式,好比字符串和圖片文件,必須在表單設置提交的壓縮類型爲multipart/form-data.
2.要解析這種壓縮格式的數據須要在springmvc配置文件中添加multipart類型解析器.
<!-- 文件上傳 -->
<bean id="multipartResolver"
class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<!-- 設置上傳文件的最大尺寸爲5MB -->
<property name="maxUploadSize">
<value>5242880</value>
</property>
</bean>
3.加上springmvc圖片組件jar包
4.建立圖片虛擬目錄存儲圖片
或者在tomcat/conf/server.xml下
注意:在圖片虛擬目錄 中,必定將圖片目錄分級建立(提升i/o性能),通常咱們採用按日期(年-月-日)進行分級建立.
5.上傳頁面部分代碼
<tr> <td>商品圖片</td> <td> <c:if test="${item.pic !=null}"> <img src="/pic/${item.pic}" width=100 height=100/> <br/> </c:if> <input type="file" name="pictureFile"/> </td> </tr>
6.添加controller映射model,保存圖片路徑名稱
Json數據交互的應用場景普遍,基本上每一個網站都會有這樣的數據交互,特色是數據交互量小,輕便,可異步刷新.
1.json數據交互思路
客戶端請求json串(或者鍵值對) <--------> 服務端json對象
2.springmvc採用jackson包來轉換json串與json對象,因此要添加jar包
3.配置json轉換器
<!--註解適配器 --> <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter"> <property name="messageConverters"> <list> <bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter"></bean> </list> </property> </bean> <!--若是使用<mvc:annotation-driven /> 則不用定義上邊的內容 -->
4.測試請求json串和key/value,輸出json串
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>json交互測試</title> <script type="text/javascript" src="${pageContext.request.contextPath }/js/jquery-1.4.4.min.js"></script> <script type="text/javascript"> //請求json,輸出是json function requestJson(){ $.ajax({ type:'post', url:'${pageContext.request.contextPath }/requestJson.action', contentType:'application/json;charset=utf-8', //數據格式是json串,商品信息 data:'{"name":"手機","price":999}', success:function(data){//返回json結果 alert(data); } }); } //請求key/value,輸出是json function requerstKeyValue(){ $.ajax({ type:'post', url:'${pageContext.request.contextPath }/requerstKeyValue.action', //請求是key/value這裏不須要指定contentType,由於默認就 是key/value類型 //contentType:'application/json;charset=utf-8', //數據格式是json串,商品信息 data:'name=手機&price=999', success:function(data){//返回json結果 alert(data.name); } }); } </script> </head> <body> <input type="button" onclick="requestJson()" value="請求json,輸出是json"/> <input type="button" onclick="requerstKeyValue()" value="請求key/value,輸出是json"/> </body> </html>
package com.harry.controller; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestBody; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.ResponseBody; import com.harry.entity.ItemsCustom; @Controller public class JsonController { //請求json串(商品信息),輸出json(商品信息) //@RequestBody將請求的商品信息的json串轉成itemsCustom對象 //@ResponseBody將itemsCustom轉成json輸出 @RequestMapping("/requestJson") public @ResponseBody ItemsCustom requestJson(@RequestBody ItemsCustom itemsCustom){ //@ResponseBody將itemsCustom轉成json輸出 return itemsCustom; } //請求key/value,輸出json @RequestMapping("/responseJson") public @ResponseBody ItemsCustom responseJson(ItemsCustom itemsCustom){ //@ResponseBody將itemsCustom轉成json輸出 return itemsCustom; } }
RESTful是一種開發理念,並不是指具體的技術,理念的闡述具體以下:
1.對url進行規範,寫RESTful格式的url
非REST的url:http://...../queryItems.action?id=001&type=T01
REST的url風格:http://..../items/001
特色:url簡潔,將參數經過url傳到服務端
2.http的方法規範
不論是刪除,添加,更新,使用url是一致的,若是進行刪除,須要設置http的方法爲delete,同理添加.
後臺controller方法:判斷http方法,若是是delete執行刪除,若是是post執行添加。
3.對http的contentType規範
請求時指定contentType,要json數據,設置成json格式的type.
示例
1.controller定義映射使用RESTful風格的url,將查詢信息的id傳入controller.
@RequestMapping(value="/ itemsView/{id}"):{×××}佔位符,請求的URL能夠是「/viewItems/1」或「/viewItems/2」,經過在方法中使用@PathVariable獲取{×××}中的×××變量.
@PathVariable用於將請求URL中的模板變量映射到功能處理方法的參數上. 若是RequestMapping中表示爲"/ itemsView /{id}",id和形參名稱一致,@PathVariable不用指定名稱.
2.配置前端控制器
"*.action"的解析在RESTful風格下會致使靜態資源沒法訪問,這裏替換成"/";
3.springmvc.xml中配置靜態資源映射
攔截器能設置請求前,響應後進行攔截執行特定的代碼,SpringMVC定義攔截器須要實現HandlerInterceptor接口.
接口中提供三個方法分別在handler執行前,後還有ModelAndView返回前執行
package com.harry.interceptor; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.springframework.web.servlet.HandlerInterceptor; import org.springframework.web.servlet.ModelAndView; public class HandlerInterceptor1 implements HandlerInterceptor { //進入 Handler方法以前執行 //用於身份認證、身份受權 //好比身份認證,若是認證經過表示當前用戶沒有登錄,須要此方法攔截再也不向下執行 @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { System.out.println("HandlerInterceptor1...preHandle"); //return false表示攔截,不向下執行 //return true表示放行 return true; } //進入Handler方法以後,返回modelAndView以前執行 //應用場景從modelAndView出發:將公用的模型數據(好比菜單導航)在這裏傳到視圖,也能夠在這裏統一指定視圖 @Override public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception { System.out.println("HandlerInterceptor1...postHandle"); } //執行Handler完成執行此方法 //應用場景:統一異常處理,統一日誌處理 @Override public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception { System.out.println("HandlerInterceptor1...afterCompletion"); } }
針對HandlerMapping的攔截器(不推薦使用)
完成攔截器編寫後須要在HandlerMapping處進行定義,畢竟攔截器是映射階段進行工做的.
package com.harry.interceptor; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.springframework.web.servlet.HandlerInterceptor; import org.springframework.web.servlet.ModelAndView; public class HandlerInterceptor1 implements HandlerInterceptor { //進入 Handler方法以前執行 //用於身份認證、身份受權 //好比身份認證,若是認證經過表示當前用戶沒有登錄,須要此方法攔截再也不向下執行 @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { System.out.println("HandlerInterceptor1...preHandle"); //return false表示攔截,不向下執行 //return true表示放行 return true; } //進入Handler方法以後,返回modelAndView以前執行 //應用場景從modelAndView出發:將公用的模型數據(好比菜單導航)在這裏傳到視圖,也能夠在這裏統一指定視圖 @Override public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception { System.out.println("HandlerInterceptor1...postHandle"); } //執行Handler完成執行此方法 //應用場景:統一異常處理,統一日誌處理 @Override public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception { System.out.println("HandlerInterceptor1...afterCompletion"); } }
全局性攔截器
<!--攔截器 --> <mvc:interceptors> <!--多個攔截器,順序執行 --> <!-- 登錄認證攔截器 --> <mvc:interceptor> <mvc:mapping path="/**"/> <bean class="com.harry.interceptor.LoginInterceptor"></bean> </mvc:interceptor> <mvc:interceptor> <!-- /**表示全部url包括子url路徑 --> <mvc:mapping path="/**"/> <bean class="com.harry.interceptor.HandlerInterceptor1"></bean> </mvc:interceptor> <mvc:interceptor> <mvc:mapping path="/**"/> <bean class="com.harry.interceptor.HandlerInterceptor2"></bean> </mvc:interceptor> </mvc:interceptors>
攔截器的應用
好比:統一日誌處理攔截器,須要該 攔截器preHandle必定要放行,且將它放在攔截器連接中第一個位置.
好比:登錄認證攔截器,放在攔截器連接中第一個位置.權限校驗攔截器,放在登錄認證攔截器以後.(由於登錄經過後才校驗權限)
攔截器實現登錄認證
1.處理邏輯
用戶請求頁面
攔截器進行攔截
若是頁面無需訪問權限,放行
頁面須要訪問權限
session存在校驗數據,經過
session無校驗數據,轉入登錄頁面
2.登錄用Controller方法和請求頁面
package com.harry.controller; import javax.servlet.http.HttpSession; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; @Controller public class LoginController { // 登錄 @RequestMapping("/login") public String login(HttpSession session, String username, String password) throws Exception { // 調用service進行用戶身份驗證 // ... // 在session中保存用戶身份信息 session.setAttribute("username", username); // 重定向到商品列表頁面 return "redirect:/items/queryItems.action"; } // 退出 @RequestMapping("/logout") public String logout(HttpSession session) throws Exception { // 清除session session.invalidate(); // 重定向到商品列表頁面 return "redirect:/items/queryItems.action"; } }
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>系統登錄</title> </head> <body> <form action="${pageContext.request.contextPath }/login.action" method="post"> 用戶帳號:<input type="text" name="username" /><br/> 用戶密碼 :<input type="password" name="password" /><br/> <input type="submit" value="登錄"/> </form> </body> </html>
3.登錄攔截器和設置
package com.harry.interceptor; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import org.springframework.web.servlet.HandlerInterceptor; import org.springframework.web.servlet.ModelAndView; public class LoginInterceptor implements HandlerInterceptor { //進入 Handler方法以前執行 //用於身份認證、身份受權 //好比身份認證,若是認證經過表示當前用戶沒有登錄,須要此方法攔截再也不向下執行 @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { //獲取請求的url String url = request.getRequestURI(); //判斷url是不是公開 地址(實際使用時將公開 地址配置配置文件中) //這裏公開地址是登錄提交的地址 if(url.indexOf("login.action")>=0){ //若是進行登錄提交,放行 return true; } //判斷session HttpSession session = request.getSession(); //從session中取出用戶身份信息 String username = (String) session.getAttribute("username"); if(username != null){ //身份存在,放行 return true; } //執行這裏表示用戶身份須要認證,跳轉登錄頁面 request.getRequestDispatcher("/WEB-INF/jsp/login.jsp").forward(request, response); //return false表示攔截,不向下執行 //return true表示放行 return false; } //進入Handler方法以後,返回modelAndView以前執行 //應用場景從modelAndView出發:將公用的模型數據(好比菜單導航)在這裏傳到視圖,也能夠在這裏統一指定視圖 @Override public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception { System.out.println("HandlerInterceptor1...postHandle"); } //執行Handler完成執行此方法 //應用場景:統一異常處理,統一日誌處理 @Override public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception { System.out.println("HandlerInterceptor1...afterCompletion"); } }
<!--攔截器 --> <mvc:interceptors> <!--多個攔截器,順序執行 --> <!-- 登錄認證攔截器 --> <mvc:interceptor> <mvc:mapping path="/**"/> <bean class="com.harry.interceptor.LoginInterceptor"></bean> </mvc:interceptor> </mvc:interceptors>